Belt dryers are put to use in many fields for drying products. It is especially in food processing, but also in other fields, that sticky products very often need to be dried which results in heavy soilage of the belt dryer. Particularly in drying food products treated with a sugary liquor the belt dryer is exposed to heavily encrusted soilage at locations due to sugary solution spillage. This is why for good hygiene and to restrict soilage the belt dryer needs to be shut down and cleaned manually at regular intervals. Such a manual cleaning procedure takes up a lot of time and money. Apart from this, there is a risk of cleaning not being comprehensive.
Automatic cleaning systems are also known in the field of cleaning production piping, tanks and receptacles by stationary nozzles emitting a suitable cleaning fluid being incorporated in the vessels to be cleaned. Such stationary nozzles cannot be put to use in belt dryers. Thus, in conventional belt guidance arrangements there is hardly any possibility, nor sufficient space for providing a means of automatic cleaning. Furthermore, very large surface areas need to be cleaned in a belt dryer which would necessitate a correspondingly high number of stationary nozzles. Apart from this, the drying process would be obstructed by such an array of nozzles, since the stationary nozzles would need to be included in the drying chamber and stay there during drying. In addition, stationary nozzles require a relatively large amount of cleaning agent.